temperature, Ventilation and Insulation are the causes of condensation, nothing else !!

Often insulation cannot be improved much so a low constant temperature and ventilation are essential....Any permeable aluminium stearate solution to outside walls will not change the apprearance ( silicone's will ) but will repel water and allow the substrate to breath thus aiding insulation and avoiding temperature drop.

Dehumidifiers work fine but don't be fooled into thinking the five litres of water you take out of the unit every day is coming out of the fabric of the building...most of it is from day to day living conditions i.e washing, ironing, breathing, bathing etc., even boiling the kettle a few times a day adds moisture..Locate the coldest rooms in the house ( look for the black spot mould) and fit a small extractor fan with a humidistat to promote air changes that will expel any moisture laden air. anyone with any condensation problem should never resort to mobile gas heaters as they can only aggravate things by the moisture they produce.....not a problem when it's warm but it's obvious where it ends up when the temp falls...more black spot mould in corners, behind close fitting furniture, on leather belts.shoes or anything made from animal hide. Keeping windows open is fine but the problems are not generated during the warmth of the day but at night when the temperature drops and the moisture laden air condenses on to cold surfaces.

Most of the anti condensation products applied to internal walls only add moisture which in turn makes the walls colder still, but they do disguise the problem by killing the mould.

We used the product as suggested by Morerosado, Sista Bano Sano anti-moho. and all the mould has gone, so thanks for the suggestion. I am hoping it won't come back. We won't be using the mobile gas heater as much now as its warmer now. I know that it is the heater that has caused the condensation and mould. I think a dehumidifier is the best option and will look into buying one to avoid any further mould.

Freddy & Surveyor, I know you are right about not using the gas heater but we have to keep warm somehow. After 2 years of high bills in the winters from using oil filter heaters, I rather not go there again!

I think the problem very often is ignorance and as you say, you do have to have affordable heating and quite often the mobile heater is the way to go...By you just knowing that they produse much moisture will allow you to ventilate when you can..during the warmers spells, during the afternoons maybe...Although I worked in the industry and know what causes what, I still have a mobile heater for the very reasons that you mention...Just being careful and watchful and you can enjoy cheaper heating and a relatively damp free property....Good luck.

Every winter, the room below our neighbours terrace suffers from flaking-off paint and the appearance of a fluffy white 'mould' in exposed areas of wall, re-appearing every day after being brushed off ! There is no evidence of wetness inside but I imagine that its damp which mkes the paint flake off on the 2 affected walls. After a sustained period of rain in Estepona earlier in March, the lawn butting up to the building was saturated for days, and I began to wonder if the damp issue is top-down or bottom-up ! Would value an opinion on how to determine this . The building is over 50 years old with no damp-proofing

The white fluffy mould is more than likely salt, it is a very common problem especially in areas with a high water table, the ground can be very salty ! Damp will only rise a metre high from ground level, this is because of the weight of the water. If the damp is higher than this it could be caused by a exterior problems with roof or windows etc.

If as it is suggested in an earlier thread that Spanish paint (plastic) can exacerbate condensation, is there a way that you can remove this paint without damaging walls etc and repaint with English type paint that breaths?

Most of the folks face the problem of damp. There are a lot of home remedies for removing damp.However, most of them give a temporary solution for this problem. I had faced this problem before two years. At that time i had decided to get some dehumidifier. But expert also gave me other solutions during buying this.I used them properly. Now, I have been not facing any problem for 2 years. Expert suggest me:1) Use dehumidifier for proper condensation 2) polystyrene-backed paper as wallpaper 3) proper Ventilation 4)Always clean walls in a month.